Workholder for lens blanks



1934' o. G. HAUSSMANN WORKHOLDER FOR LENS BLANKS Filed Dc. 16. 1952 2Shets-Sheet 1 Otto GHaQL/ssmamn 1934' o. G. HAUSSMANN WQRKHOLDER FORLENS BLANKS 2 Sheets-Sheet 2 Filed D90. 16. 1932 0170 a/iaussmcwfi vPatented Aug. 7,

UNITED STATES PATENT Omar-q 1,969,219 V I WORKHOLDER FOR LENS- BLANKSOtto Gustave Haussmanmlhiladelphia, Pa. Application December 16, 1932,Serial bio. 647,659 9 Claims. (01; 51 -217) This invention relates toawork holder for lens blanks especially applicable to the manufacture offused bifocal and fused multi-focal lenses, in which it is necessary togrind and polish one or more depressions or counter-sinks in the glassblank for the purpose of grinding one or more lenticular facets in theblank into which a glass button of higher refractive index is seated andfused, bringing about in'the fused lens blank, a variation of focalpowers.

It is customary in the grinding of all ophthalmic lenses to mount theblank on the work holder by means of pitch. It has not been attemptedinsofar as I am aware to clamp the blanks in the Work holder without theuse of pitch or other adhesive. The so-called fsticking up of the lensis attended with certain inherent disadvantages; the pitch must bewarmed to the .proper consistency, otherwise the blank will fly offwhile being ground; the pitch is subject to cracking during the grindingoperation through any one of a number of causes, and it requires to beimmersed in-ice water at the end of the grinding operation in order todetach the lens from the pitch. A certain pro- Another object oftheinvention is to providemeansfor mounting the lens holder tiltably,

with adjustment for tilt so that the' blank can be presented tothegrinding lap at different,

angles, for varying the shapes, sizes and depths of the ground facets.In grinding a multi-focal lens, that is to say, one which has more thantwo focal fields, a diiferent setting is requiredfor each field. Thedistant field, the transition field and the reading field can each beground and polished by a setting of the blank holder which merelyrequires tilting the lens holder at various angles. Where there arelateral fields, the centers of-which are radially displaced, itbecomesnecessary not only to tilt the lens blank holder, but also to give it apartial rotation and the means for imparting this rotation independentof the position of tilt constitutes a further object of the invention.

Still an r v I mountingof a plurality of the lens blank-holderssymmetrically to an axis'and providing means ther object of theinvention is the for imparting to them an identical variation of v tilt,and providing also means for rotating them through identical arcsirrespective of the posi--' a tion of tilt through means selectivelyoperable.

Other. objects ofthe invention will appear as the following descriptionof a preferred and practical; embodiment thereof proceeds. I

Referring ,now to the accompanying drawings whichform apart of thefollowing specifica-"- tion and throughout the several figures of which,the same characters of reference have been employed to designateidentical'partsz' Figure 1 is a plan view of the workholder'forlensblanks in which three lens blank holders are employed; Figure 2 is asection taken along the lined-2': of Figure 1, the work holderbeingfshown in 011- erativef relation to a convex grinding lap; 1'

Figure 3 is a section taken alongthe line"3'3 of Figure 1;, i 5

Figure 4 is a section takenalong the line 4- 4' of Figure 1; Y

Figure 5 is a section taken along the line.

of Figure 2, viewed from beneath; I

element of the lens blank holder; and

Figure Us a sectional view through a concavew Referring the numeral 1-representsa base or support having Work holder to frictionally embracethe tapered oldera central hub; 2, the, hub being: providedwith atapered socket 3 adaptedin one utilization of the end'of-a. rotatingspindle,-for rotating the work It' is immaterial insofar as theinventive con-1 cept is concerned howmany. lens blank ,h0lder's 1 aresupported ,on thebase 1, the present illustrae. Itive embodiment showingthree, each of whichis carriedabya bracket 4,- said-brackets being'syme-metrically arranged and carrying axles 5'in suitable bearing-.lugsfj.The prolongationsaof the axes of said axles intersect in the angles ofan equilateral triangle, the altitudesof whichtr'i -;1 angle intersectat a common point in the axis of rotation of the base 1. Each of thelens blank holders comprises a frame '7; preferably circular 9 andhaving bearing lugs 8 extending from'its lower face and journalled uponan axle 5,. Thus the frames 7 are'tiltably mounted upon said axles;Thehub 2 is externally threadedas shown at 9'in'q ;Figure 2,; andcarries a ring nut 10 which travelsv in and out relatively to said hubwhen screwed Figure 6 is a perspective View of the revoluble fl saidworm, said lens seats are simultaneously revolved.

5. Work holder for lens blanks as claimed in claim 4 including means forsimultaneously tilting the tiltablymounted elements of said lens blankholders.

6. Work holder for lens blanks comprising a rotary element, a pluralityof lens blank holders symmetrically and tiltably carried eccentricallyby said element, means for simultaneously adjusting the angle of tilt ofsaid lens blank holders, said lens blank holders each including a lensholding element revoluble independently of the angle of tilt of saidlens blank holders.

7. Work holder for lens blanks as claimed in claim 2, including an axlefor each lens blank holder on which the latter is tiltably mounted, eachlens blank holder including a revoluble lens seating member, a gearconnection between said axle and lens seating member, a master gear, agear connection between said master gear and each of said axles, andmeans for revolving said master gear. 7

8. Work holder for lens blanks comprising a support, a lens blank holderon said support ineluding means forming a seat for the lens blank, saidmeans having an abutment, a clamping element pivoted on said lens blankholder at a point below the plane of said seat and on the opposite sidefrom said abutment comprising a bell crank lever having one arm of suchlength as to engage the edge of the lens blank, and a screw engaging theopposite arm of said bell crank lever and. abutting against said supportfor rocking the end of said lens blank engaging arm inwardly anddownwardly, forcing said blank both against said abutment and againstsaid seat.

9. Work holder for lens blanks comprising a support, lens blank holdersarranged on said

